Cast steel door for hopper dump cars



Jan. 14, 1941. I A. CAMPBELL CAST STEEL DOOR FOR HOPPER DUMP CARS Original Filed July 2. 1938 Patented Jan. 14, 1941 UNITED STATES PATENT OFFICE CAST STEEL DOOR FOR HOPPER. DUMP CARS i Argyle Campbell, Chicago, Ill.', assignor to Enterprise Railway Equipment Company, Chicago, 111., a corporation of Illinois Original application July 2, 1938, Serial No. 217,250. Divided and this application March 6, 1940, Serial No. 322,586

2 Claims.

This application is a division of my co-pending application, Serial No. 217,250, filed July 2, 1938, relating to hopper construction for railwaydump cars. In that application cast steel is used in the construction of the hopper door frame and lower portion of the hopper itself because of its resistance to corrosion as compared with sheet metal or commercial plate commonly used in hopper construction.

Cast steel is for the same reasons particularly desirable for door construction, but heretofore attempts to utilize cast steel has resulted in door construction which is entirely too heavy and cumbersome to be practicable, due primarily to the necessity of forming thick, heavy casting, and to distortion which occurs by shrinkage or contraction during the cooling of the casting in the manufacture of the door.

My present invention involves an integral cast steel door of relatively light weight, thin construction throughout its area, with special means which compensates for shrinkage and thereby prevents distortion in the manufacture of the door, and which in the completed door serves to rigidify and strengthen the door in the direction of greatest stress both longitudinally and transversely of the pivotal axis of the door.

Referring to the accompanying drawing:

Fig. 1 is a view in elevation of the outer face of a cast steel hopper door embodying my invention;

Fig. 2 is a transverse sectional view substantially on the line 2-2 of Fig. 1;

Fig. 3 is a longitudinal sectional View substantially on the line 3-3 of Fig. 1;

Fig. 4 is a detail sectional view on line 4-4 of hopper frame with which the door cooperates.

The door is substantially rectangular in shape except that at one end the margin is angularly disposed, making the structure wider at the top than at the bottom to conform to the discharge opening formed by the door frame. At the upper or hinge edge the casting has integral hinge butts 2, attachable to the door frame and providing the pivotal axis of the door.

The margins of the hopper door frame structure provide an even bearing surface against which the door bears, and the door has for this purpose a fiat bearing surface 3 extending all around adjacent the marginal flange I. It is essential, therefore, that the door itself be free from distortion so that its bearing surface 3 will properly bear against the door frame and provide a close fit therewith throughout its contact area.

In order to relieve the casting of the strains due to shrinkage, which otherwise distort and twist the casting while the casting is cooling, I provide the casting with a corrugation or depressionB which, because of its form, acts to compensate for the shrinkage and thereby prevents the shrinkage from applying distorting strains to the casting. This corrugation is in the form of an inverted T with its headA disposed contiguous to and parallel with the swinging or free edge of the door, and its stem 5 disposed substantially at right angles to the head and extending transversely of the casting substantially midway of the width thereof.

The corrugation is formed by making a portion of the sheet of the casting substantially semicircular in section beyond the plane of the rest of the sheet, so that it forms a protuberance or ribs instanding from the inner face of the casting on the same side as the marginal flange I. The side wall portions 6 of the corrugation extend at an angle to the plane of the casting so that during cooling of the casting any shrinkage strains which occur in the body of the casting in the directions of the plane thereof will act to widen the corrugation by pulling on the side wall portions 6. In this manner the shrinkage strains are compensated for and are prevented from extending to the marginal flange l of the casting. The disposition of the corrugation ribs Provides for absorbing the shrinkage strains in all directions within the body of the casting. For instance, strains extending lengthwise of the casting will be absorbed in the stem 5 of the T, while those extending transversely will be absorbed by the head 4 of the T. Diagonal strains will be absorbed by both the stem and head. It is important, therefore, that the head and the stem merge at the juncture l, as shown in the drawing. At the juncture the side Wall portions 6 of the head and stem merge with each other on a curve of relatively large radii, instead of an angular relation, to prevent shrinkage cracks at these points. The ends 8 of the stem and head portions are tapered so that their walls gradually merge into the plane of the body of the casting, it

margins of the casting. After the casting has cooled and set, the shrinkage strains have thus been compensated for and have had no effect in distorting the casting. The corrugated T rib then becomes a rigid reinforcement for the casting to strengthen the door in the directions of greatest stress, both horizontally and transversely, to which the structure is subjected in use.

In the drawing, the door is illustrated as having a latching mechanism which constitutes subject matter of my parent application above mentioned, of which this present application is a division. This latching mechanism comprises a latching bar l pivoted at one end II on a boss 12 formed on the door casting. This latch engages a keeper (not shown) which extends through an opening in the door and is carried by the hopper door frame. The latch bar is guided by a plate member I 3 which is suitably secured at four points M to the door plate, in the present structure this plate being to overlie the juncture of the head and stem of the T-shaped corrugation ring. A suitable locking dog I5 is also provided for holding the latch in place.

I claim:

1. A door for the hopper of railway dump cars, comprising an integral one-piece metal casting including a flat relatively thin plate-like body portion having a continuous flange bordering its margin, and having a unitary hollow reinforcing corrugation above its surface, of T-shape in formation with the head of the T disposed substantially parallel with and contiguous to the free or swinging edge of the door and extending to points contiguous to the side edges of the door, and the stem of the T disposed transversely of the door substantially midway of its length and extending to a point contiguous to the upper edge of the door, the walls of said hollow corrugation merging with the body portion at an angle to the plane thereof, the said walls of the head and stem of the T merging on a relatively large curve.

2. As an article of manufacture, a cast metal door for hopper bottom cars having a plate-like area body and an upwardly extending flange around the four sides of the plate-like area body for stiffening the edges thereof and for enclosing the hopper, a horizontally disposed corrugation extending adjacent the lower free edge of the door from points adjacent the side edges, and a vertical corrugation intersecting said horizontal corrugation intermediate the sides of the door and. extending to a point closely adjacent the upper edge of the door, the two aforesaid corrugations dividing the body into three panel areas and forming yielding means along at least one margin of each panel area to compensate for contraction in each panel during the period of transition from soft hot metal to the cool and hard form, said corrugations providing stifiening means to the plate-like area body as a whole in lateral and vertical directions, for strengthening the finished door against distortion in service.

ARGYLE CAMPBELL. 

